Electronic apparatus



Jan. I5, 1946. A. BINNEWEG, JR 2,392,900

v ELECTRONIC APPARATUS I Y Filed oct. 15, 1942 lllmlllllll n* El,

INVENTOR Patented Jan. 15, 1946 ocurren STATES ATENT OFFICE 4 Claims.

My invention relates to improvements in radio tube construction and accessory apparatus for the synchronous tuning of circuits and the objects cf my improvement are, first to provide a novel vacuum chamber with dual sets of radio elements as illustrated. A second object is to mount the tube elements upon bars athwart the vacuum chamber, and to project the bars through the Walls of the chamber as leads and so aiiord means for a variety of circuit connections. Further ob' jects are to provide special variable condensers in an outer vacuum chamber with controls therefor. The unit with its easily accessible leads may be used as a Whole or in part for a variety of purposes, as for detecting, tuning, amplifying, and the like. The unit is especially adapted for eX- perimental and instructional use. A further object is to provide a single control for condensers in adjoining circuits so that both may be tuned synchronously over a considerable frequency range. The unit is especially adapted for use in a two-stage radio-frequency amplifying circuit. A special object is the elimination of internal tube inductance and capacitance, and the reduction also of external inductance.

The usual radio-frequency amplifier is difficult to adjust because of the inductance and capacity of lengthy leads in and between tubes; and the two tuned circuits are diicult to keep in resonance at the same frequency when the dial is rotated. My novel direct connection between external condensers and grids or other radio parts Within the vacuum chamber corrects this condition and makes possible a workable tuner for very high frequency receivers or transmitters requiring one, or more tuned circuits.

Figure I is a plan view of the unit with covers removed; Figure II is a vertical section taken near one end; and\Figure III a top View detail. Figure IV is a fragmental plan View in detail of a corner of Fig. I.

Vacuum or closed chamber l, enclosed by walls 2 and cover 3, contains an inner vacuum chamber 4 with Walls 5 and cover 6 and a variable condenser having rotary plates 'l and stationary or movable plates 3. By means of knob 9 condenser shaft lll, mounted in suitable bearings ll, may be turned. Condenser plates 1 affixed to shaft Ill, may be moved close to the stators 8 for large capacity effect, or away therefrom as shown in Figure II for decreased capacity. The condensers could also be Xed as to capacity and have air or solid dielectric.

Plastic contact members l2 and I2' with metal tips I4 hold metal balls or parts, i3, which are pressed against one or both sides of the shank 3U or the plate itself of the moving condenser plate l by springs i6. The lead wire I1 does not move as the condenser is adjusted, and so changing inductance and capacity effects are obviated The shank could be omitted and the plate mounted directly on the shaft if desired.

The member l2' is supported by bracket 3| attached to the case 2. The lead Il is attached to one of several conductors 32 penetrating the case 2 and securely cemented in the wall.

Within the inner vacuum chamber 4 are usually a pair of element sets, each comprising, for example, a cathode I8, a plurality of at circular grids I 9 with cross wires 21, and a plate 20. The elements are supported by pins or inserted lugs 2| which pass through the Walls of the vacuum chamber 4 and so provide means for inside element removal and outside electric connection. These leads provide means for the shortest possible direct connection with other parts of the radio or television circuit; and so make possible shorter circuits, greater efficiency and higher frequencies than the usual arrangement Where leads pass down through tube bases and sockets, or Where the leads must curve around a tube and around a condenser.

The condenser plate 8 is integral with grid pin 22. yExhaust tubes 23 are provided for the removable covers of both vacuum chambers. Fixed condenser 24, or any other desired piece of apparatus, may be connected in the sameA direct way to any plate or other grid element within the chamber l as desired.

Plastic is preferred for tube and case Walls. The tube chamber can be iixed or movable inside the radio unit.

The condenser shaft can be of plastic. The rotor plate should have the contact ball of Figure III conveniently arranged to maintain contact with the plate. The usual inductance from the current entering the plate by Way of the shaft when the shaft is of metal rather than plastic is eliminated by this design. The movable plates can be made adjustable along the common condenser shaft. Novelty also rests in having a single condenser and an associated tube element arranged for streamline effect. Radio parts could also be arranged in the tube case, directly connected to the tubes elements.

, I claim:

1. A radio unit having an inner vacuum chamber, flat plate and grid elements Within said chamber, leads supporting said elements and passing through the Walls of said inner chamber,

an outer vacuum chamber surrounding said inner chamber, and condenser stators attached to certain of said leads.

2. The combination of a `Vacuum chamber, electrode elements Within said chamber, variable condensers adjoining said chamber and electrically connected with certain of said elements, a second Vacuum chamber enclosing both said rst chamber and said condensers, `and means outside said second chamber for Varying the capacity of said condensers.

3. The combination in a radio unit of a vacuum chamber, a at grid within said chamber, a flat stator condenser plate in the same plane with said grid and connected therewith adjacent to said chamber, a rotor plate in spaced proximity to said stator plate, a shaft mounting said in spaced proximity to said stator plate, a at shank for said rotor plate, metal balls bearing upon opposite sides of said shank, springs pressing said balls into electric contact with said shank, metal tips holding said balls, leads connecting with said tips, and plastic supports for said tips and said springs.

ABRAHAM BINNEWEG, J R. 

